1. Field of the Invention
The present invention relates to a pulley for use with a toothed belt. More particularly, the present invention relates to a pulley for use with a tooth belt which is capable of conveying a rotary movement by engaging with the toothed belt.
2. Description of Related Art
One pulley 500 currently known in the art for use with a toothed belt is shown in FIG. 6. The pulley has teeth 501 provided around an outer circumference thereof which engage with the toothed belt and flanges 550 erected on both lateral sides of the toothed belt. The flanges 550 suppress the toothed belt from wobbling in a width direction thereof so as to convey a stable rotary movement. One problem with this configuration, however, is that air can become compressed between the toothed belt and pulley when the toothed belt engages with the teeth 501. As the air is compressed, the air discharges through the small gap between the sides of the toothed belt and flanges 550, resulting in very large pneumatic and explosive sounds.
One method for reducing this noise is described in Japanese Patent Application 2007-276939, where the compression noise is reduced by letting air out before the pulley engages with the toothed belt, as described on page 4 of the application and shown in FIG. 3. As shown in FIGS. 7 through 9, this known pulley 600 reduces the noise using a series of incisions 602 formed on the teeth 601 so as to channel air from the incisions 602 to dedendums 603 before the pulley 600 engages with the toothed belt 610 and to reduce the noise otherwise generated when the compressed air leaks out of the gap, as described in pages 3-5 and FIGS. 1-3 of Japanese Utility Model Application No. Sho. 62-87251 gazette.
One problem with this configuration, however, is that the manufacturing cost sharply increase due to the additional manufacturing processes required to form the incisions 602. Additionally, production efficiency decreases. Furthermore, the known pulley 600 also has a low noise reducing effect because the amount of air released through the incisions 602 because a depth of the incisions 602 is limited by a height of the teeth 601. Furthermore, noise is still generated as air is compressed through the incisions 602
Accordingly, the present invention aims at solving the problems of the prior art technologies described above by providing a pulley for use with a toothed belt which is capable of reducing noise while reducing the manufacturing costs, increasing production efficiency, which is capable of stably conveying a rotary movement by suppressing the toothed belt from wobbling in the width direction.